The nature of the truck and van marketplace requires truck and van assembly plants to be capable of painting vehicles in a wide variety of custom colors. Generally, vehicle assembly plants utilize paint circulating systems that require from 20 to 60 gallons of paint to fill the system. Since the amount of paint required to paint a single truck or van is approximately 2 to 3 gallons, there is considerable paint waste associated with painting a single vehicle with a relatively small quantity of custom colored paint. Additional cost is also incurred in cleaning large relatively elaborate paint circulating systems.